U.S. President Barack Obama marked the end of more than a decade of combat in Afghanistan by paying tribute to America's military on Christmas Day.

At a Marine Corps base in Hawaii on December 25, Obama told troops that their dedication and sacrifices have allowed for a more peaceful, prosperous world to emerge in the wake of the September 11, 2001 terrorist attacks.

"Because of the extraordinary service of the men and women in the American armed forces, Afghanistan has a chance to rebuild its own country," Obama said. "We are safer. It's not going to be a source of terrorist attacks again."

The United States and NATO are withdrawing most their troops out of Afghanistan by year's end, leaving 13,500 behind for training and battlefield support.